Two of my dogs had heartworms when I got them from the shelter. While it isn't a good idea to wait any longer than necessary, it is also not an emergency. It isn't contagious so other dogs can't get it from the infected one. But all of the dogs in a household should be checked.

The treatment involves a day at the vets where they administer medication in a vein. Usually the dog can go home the next day. In three weeks another shot and the dog goes home right away. The dog should be kept relatively quiet for the whole time. Another test is usually done after about three more weeks.

There was no way I could keep mine quiet for six weeks!! I would guess that if the heartworms were in an advanced stage, the heart would be pretty weak. This would cause a lot of activity to strain the heart more than it could take. Young dogs can handle it better than older dogs. One of mine was 12 when he had it done. They both came through with flying colors.

Heartworm is transmitted by infected mosquitos. Even indoor-only dogs should be on heartworm medication regularly.

Hope this info helps.

Mary